Team CryptoInsightfull 
3. bitcoin.org
bitcoin.org/en/download lists
| Platform | Package |
|---|---|
| Windows | exe – zip |
| macOS (x86_64) | zip – tar.gz |
| macOS (arm64) | zip – tar.gz |
| Linux 64 bit | (tgz) |
| ARM Linux 64 bit – 32 bit | – |
| RISC-V Linux 64 bit | – |
| PPC64 Linux 64 bit – 64 bit LE | – |
| Linux (Snap Store) | snap |
For your contemporary hardware based on Intel x86 / AMD x64 compatible architecture, the appropriate choice from that list would be
Linux 64 bit (tgz)
2. bitcoincore.org
However, in my opinion, bitcoin.org is the wrong website to use. I would always prefer to use https://bitcoincore.org/en/download/
See Is bitcoin.org or bitcoincore.org the one to trust?
1. Native package manager
But first of all I would check the native package manager for the installed Linux distribution (e.g. apt for Ubuntu and many distributions based on Debian, yum for many distributions based on RedHat) and see if that native package manager has the most recent version of Bitcoin core
This is especially true if you believe you are “not technically proficient” – Use the package manager icon on the graphical desktop.
Postscript
OS name: Ubuntu 20.04
20.04 dates from around 2019 is out of desktop and server support though it still has security updates. Current version of Ubuntu with long term support (LTS) is 24.04 – I would upgrade to that.
